Hey Jiri.
Thanks for getting back.
On Friday, April 4, 2014 4:48:48 PM CEST, Jiri Bourek wrote:
- where did I fail (ignoring the backups, please. That's .. something I know)
From the man page: "backup - Backup mails from default mail location to location2 (or vice versa, if -R parameter is given). No changes are ever done to the source location. Any changes done in destination are discarded."
Yeah, maybe. That's what I thought _after_ the fact (i.e. that was what I hinted at with 'one way sync'). But see below.
The last sentence describes what happened to you: all new mail on the new machine is a "change" and was discarded (by deleting new mail.) If I'm not mistaken, this is correct behaviour for backup mode - you get exact copy of the source side (maildir:/tmp/mail_backup) on destination side (dar@darklajid.de)
That would be sort of okay. Except that isn't what happened:
- The target mailbox was killed completely
- Nothing was restored
If what you're suggesting here is true I'd expect a clean copy of my source
- even if it destroys all other changes. That did NOT happen though. It nuked the target and didn't restore a thing.
Plus, dsync mirror did exactly the same: Nuked the (live) mailbox once more, same error message, not a single message restored (but also no modification to the source).
- Can I use dsync ... for backups? I don't think that this is a good idea after yesterday night?
AFAIK you can safely use it to make the backup. I'm not sure if it can be reliably used to restore data (don't think so but I'm not an expert.) I'd use doveadm import for that.
That'd be my experience at this point as well, of course. :-) The bigger question is if this is well-known / correct and if this should be documented in a better fashion. Was I really that naive to expect that to work (in that case: ignore the documentation request) or could that happen again?
Ben